Method to produce a coating layer, a building panel and a coated foil

ABSTRACT

The present disclosure relates to a method to produce a coating layer, including applying a coating composition on a surface of a carrier, curing the coating composition to a coating layer, and subsequently applying pressure to the coating layer. The disclosure further relates to a method to produce a building panel, and such a building panel, and to a method to produce a coated foil, and such a coated foil.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of Swedish Application No.1750641-1, filed on May 23, 2017. The entire contents of SwedishApplication No. 1750641-1 are hereby incorporated herein by reference intheir entirety.

TECHNICAL FIELD

Embodiments of the present invention relate to a method to form acoating layer, a method to form a building panel, such a building panel,and a method to form a coated foil, such as coated foil.

TECHNICAL BACKGROUND

In recent years, so-called Luxury Vinyl Tiles and Planks (LVT), WPC(Wood Plastic Composite) and SPC (Stone Plastic Composite/Solid PolymerCore) floorings have gained increasing success. These types of floorpanels usually comprise a thermoplastic core, a thermoplastic décorlayer arranged on the core, a thermoplastic transparent wear resistantlayer on the décor layer, and a coating applied on the wear resistantlayer. The thermoplastic material is often PVC. The core may comprisefillers, such as limestone. Although often named WPC floorings, thefiller in the core may for some products not be wood but, for example,limestone. The wear resistant layer is conventionally a PVC foil, forexample, having a thickness of 0.2-0.7 mm. The core, the décor layer andthe transparent wear resistant layer are conventionally pressed togetherto form the floor panel. The coating applied on the wear resistant layerafter pressing is conventionally a UV curing polyurethane coating. Thewear resistant layer together with the coating provide the wearresistance of the floor panel and protect the décor layer. Afterpressing, in a subsequent and separate step, the UV curing polyurethanecoating is applied on the surface of the wear resistant layer. Byapplying a UV curing polyurethane coating as an uppermost layer to thefloor panel, the surface of floor panels obtains a uniform gloss level,i.e., the floor panel obtains the gloss level of the coating.

Since embossing of the wear resistant layer is performed duringpressing, by pressing the wear resistant layer against an embossed pressplate, or similar, the coating applied after embossing may make theembossed surface of the wear resistant layer more even, such that theeffect of the embossing is reduced, at least visually.

However, when subjecting floor panels to wear, it has been shown thatthe coating and the wear resistant layer are relatively easily worndown, or at least worn such that the appearance of the wear resistantlayer is affected, such as having scratches and/or not being transparentany longer. Compared to a conventional laminate floor panel, the wearresistance of an LVT floor panel is inferior. However, LVT floors offerseveral advantages over, for example, laminate floors, such as deepembossing, dimensional stability related to humidity, moistureresistance and sound absorbing properties.

Improving properties, such as wear and/or scratch resistance, chemicalresistance and aesthetic properties, and rationalising the manufacturingprocess are general desires as this flooring category further develops.

Also, other types of floorings are provided with coatings, such as UVcurable polyurethane coatings. Wooden floorings are often lacquered withUV curable coatings, and the surface of the wooden flooring obtains auniform gloss level, i.e., the gloss level of the uppermost lacquerlayer. Improving properties of the coating in order to allow forincreasing design variations of wooden floorings would be an advantage.

WO 2016/113378 discloses a method for producing a covering, includingproducing a substrate layer, attaching a surface layer to a top side ofthe substrate layer, attaching a top side of a backing layer to a bottomside of the substrate layer and attaching a top side of a textile layerto the bottom side of the backing layer. Thereby, a sheet is provided,defined as the entirety of the surface layer, the substrate layer, thebacking layer and the textile layer. In a further step, the sheet iscured. After curing the sheet, the surface layer may be mechanicallyembossed. After curing of the sheet, in a further step, a surfacecoating may be provided on top of the wear layer as an additionalcomponent of the surface layer.

US 2014/0255670 discloses a method for printing a wood material board.The method includes printing a wood material by means of a digitalprinting technology, forming a decorative layer, applying a protectivelayer containing at least one resin, at least one radiation-curablevarnish and/or at least on polyurethane on the decorative layer, andpre-drying and/or pre-gelling the protective layer. The protective layeris only pre-dried and/or pre-gelled and is thus not yet completely driedor cured. The surface of the protective layer is rather sticky orsurface-dried. The pre-drying and/or pre-gelling is carried out to theextent that the protectively layer, i.e., the resin or varnish as suchis still free-flowing and cross-linkable. The wood material boardprinted and provided with the protective layer is processed further orfinished in a short cycle press. In the short-cycle press, the resinslayers are fused and the layer composite is cured to form a laminate.

US 2013/0011623 discloses a monolithic three-dimensional composite. Thecomposite comprises in one embodiment a three-dimensional layer and anouter layer. A print layer can be disposed on the outer layer. The printlayer may receive a wear layer by a coating means applying a polymericcomposition. The wear layer is allowed to cure. A heat source, e.g.,radiant oven, gas-fired oven, etc., may be employed to assist in curingthe wear layer. During and/or after curing, the wear layer is permittedto obtain ambient temperature. Thereafter, the surface of the wear layeris subjected to a sufficient temperature to soften the cured wear layersurface by reheating with heat source, e.g., an infrared radiant heatoven. This step softens the surface of the wear layer to permitmechanical embossing by an embossing drum.

SUMMARY

It is an object of at least embodiments of the present invention toprovide an improvement over an aspect of the above described techniquesand known art.

A further object of at least embodiments of the present invention is toimprove a coating process for substrates intended to be pressed.

A further object of at least embodiments of the present invention is toimprove chemical resistance of coatings for flooring surfaces.

A further object of at least embodiments of the present invention is toallow varying gloss levels on coatings.

At least some of these and other objects and advantages that will beapparent from the description have been achieved by a method to producea coating layer according to a first aspect of the invention. The methodcomprises applying a coating composition on a surface of a carrier,curing the coating composition to a coating layer, and subsequentlyapplying pressure to the coating layer.

By curing is meant completely curing or at least curing beyond apre-dried or pre-cured state.

An advantage of at least embodiments of the present invention is that byapplying the coating layer prior to pressing, the coating may beperformed inline, integrated with the assembling and adhering of otherlayers in, for example, a building panel. Thereby, a more rational andintegrated production method may be achieved.

At least embodiments of the present invention allow that the coatinglayer may be handled as a separate layer after curing, and be adhered toanother substrate, etc., by pressing. The coating composition may beapplied to a substrate in form of a release foil or film, and releasedfrom the release foil or film prior to pressing the coating layer toanother substrate.

A further advantage is that improved chemical resistance has shown to beachieved by pressing the coating layer. The improved chemical resistanceis believed to be achieved by the fact that the pressing furtherincreases the degree of crosslinking and/or by the compression of thecoating layer. By the higher degree of crosslinking, the higher chemicalresistance of the coating.

Furthermore, improved scratch resistance of the coating layer may beachieved, due to the higher degree of cross-linking obtained afterpressing, and/or due to the fact that the coating layer is compressed bythe pressing operation.

A further advantage is that by pressing the coating layer, also thecoating layer may be embossed by pressing against an embossed pressplate. In a conventional process, the surface of the substrate isembossed prior to the coating is applied. Thereby, the coating may fillless deep structures in the substrate and the visual impression of theembossing may be less distinguishable.

It has further been shown that pressing the coating layer may reduce anydamages, such as scratches, in the coating layer. Such scratches may beformed during the production and during handling under the productionprocess.

Applying pressure may comprise pressing the coating layer against apressing device comprising portions having different gloss levels, suchthat the coating layer obtains different gloss levels after pressing. Byapplying the coating composition prior to pressing and thereafterpressing against a pressing device having portions with different glosslevels, it is possible to obtain different gloss levels in the coatinglayer in a simplified way compared to solutions known in the art.

Applying pressure may comprise applying heat and pressuresimultaneously.

The coating composition may comprise a cross-linkable component. In across-linkable coating system, curing the coating composition crosslinksthe polymer.

The coating composition may have a residual oligomer content being lessthan 10% after curing, e.g., more than 0% and less than 10%. Having someresidual oligomer content corresponds with having some remainingcrosslinking capacity. By some crosslinking capacity of the coatingcomposition remaining after curing, the remaining crosslinking capacityfacilitates that the coating layer may be pressed after curing.

After curing the coating composition, the coating composition is nolonger sticky. Thereby, the coated carrier may be handled, such as beingrolled on a roller. By curing is meant that the coating composition haspassed its pre-dried and/or pre-gelled state, e.g. having a residualoligomer content being less than 10%.

The coating composition may be water-based. It has been found that awater based coating composition maintains capability to be re-shapedafter curing, thus facilitating the coating layer to be shaped duringpressing, for example, be embossed or be provided with a gloss level.

The coating composition may comprise a two-component system. Thetwo-component system may comprise an epoxy amine, a polyurethaneisocyanate, an isocyanate alcohol, or an acid alcohol system. Thecoating composition may be a water-based two-component system.

The coating composition may be UV-curable, preferably a water-based UVcurable coating composition. By the coating composition being UV-curableis meant that at least a component of the coating composition isUV-curable. By using a UV curable composition, curing may be performedat a higher speed compared to pure water-based coating systems. Aftercuring, a UV-cured coating layer is no longer sticky at roomtemperature, e.g. at 25° C. The surface of the coating may be hardercompared to a sintered coating composition. The UV curable component maybe a polyester/polyurethane dispersion. The UV curable component may bea polyurethane/acrylic copolymer dispersion.

Prior to pressing, a water-based UV-curable coating composition is firstcompletely dried in order to have the water to evaporate, and thereafterUV-cured, such that UV-curable components are cured. After being driedand UV-cured, the coating layer formed by the coating composition ispressed.

The carrier may comprise a thermoplastic material, preferably PVC.

The carrier may be a foil. The coating layer and the carrier may bepressed together to another substrate, or the coating layer may bereleased from the carrier after pressing.

The foil may be a thermoplastic foil. The foil may be a PVC foil. Thethermoplastic foil may be a wear resistant foil. The thermoplastic foilmay be a decorative thermoplastic foil, such as a printed thermoplasticfoil. Thereby, a coated thermoplastic foil may be formed, which may bepressed to a substrate in subsequent step. Since the coating layer iscured and pressed, the coated wear resistant or decorative foil may bestored and handled as a conventional wear resistant foil.

The carrier may be a wood-based substrate, preferably wood veneer. Inone embodiment, a wood-based substrate is coated and thereafter pressed.Thereby, the coating layer may, for example, obtain an embossedstructure by pressing against an embossed pressing device, and/or obtaindifferent gloss levels by pressing against a pressing device havingportions with different gloss levels.

Applying pressure to the coating layer may comprise pressing andattaching the coating layer on the carrier to a substrate, wherein thecarrier is intermediate the coating layer and the substrate. Thereby, acoated substrate, for example a building panel, may be provided,comprising a substrate and the coated carrier. The carrier may be athermoplastic foil. The carrier may be a wood-based material. Thecarrier is already provided with the coating layer prior to beingadhered to the substrate. Thereby, the carrier may be coated in processseparate from handling the complete substrate.

As an alternative or complement, the carrier may be adhered to thesubstrate by an adhesive.

The method may further comprise releasing the coating layer from thecarrier prior to applying pressure, and wherein applying pressure to thecoating layer comprises pressing and attaching the coating layer to asubstrate. In this embodiment, the carrier has the function of atemporary carrier, for example, a release film or foil, and the coatinglayer may be pressed to a substrate without the carrier. Alternatively,the coating layer may be released from the carrier after pressing butprior to being adhered to a substrate.

The coating composition may comprise scratch resistant particles, suchas silica particles. Thereby, the scratch resistance of the coatinglayer can be improved. The coating composition may also include wearresistant particles, such as aluminium oxide particles, also known ascorundum.

The carrier may comprise a first thermoplastic foil and a secondthermoplastic foil, wherein wear resistant particles, preferablyaluminium oxide particles, are arranged between the first and the secondfoil. The first and second foils, with the wear resistant particlestherebetween, may be pre-pressed to be adhered to each other, preferablyafter the coating has been applied. Thereby, the coated carrier forms awear resistant layer, which can be stored and handled as a separatelayer, which may be pressed to a substrate in a subsequent step.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

According to a second aspect of the present invention, a method toproduce a building panel is provided. The method comprises providing asubstrate and at least one surface layer arranged on the substrate,applying a coating composition on said at least one surface layer,curing the coating composition such that a coating layer is formed onsaid at least one surface layer, subsequently applying pressure to thecoating layer with a pressing device, and pressing the substrate and thecoated surface layer together to form a building panel.

Pressing the coated surface layer to the substrate may be performedseparate from applying the coating composition and curing the coatingcomposition to a coating layer. The coated surface layer may be stored,and pressed to the surface layer in a later step, which may be performedby another producer than the producer of the coated surface layer.

By curing is meant completely curing or at least curing beyond apre-dried or pre-cured state. An advantage of at least embodiments ofthe present invention is that by applying the coating layer prior topressing, the coating may be performed inline, integrated with theassembling and adhering other layer in the building panel. Thereby, amore rational and integrated production method may be achieved.

At least embodiments of the present invention allow that the coatedsurface layer may be handled as a separate layer after curing, and beadhered to a substrate in subsequent step, separate from the coatingstep.

A further advantage is that improved chemical resistance has shown to beachieved by pressing the coating layer. Thereby, a building panel havingimproved chemical resistance may be provided. The improved chemicalresistance is believed to be achieved by the fact that the pressingfurther increases the degree of crosslinking, and/or by the compressionof the coating layer. By the higher degree of crosslinking, the higherchemical resistance of the coating.

Furthermore, improved scratch resistance of the coating layer may beachieved, due to the higher degree of cross-linking obtained afterpressing, and/or due to the fact that the coating layer is compressed bythe pressing operation.

A further advantage is that by pressing the coating layer, also thecoating layer may be embossed by pressing against an embossed pressplate. In a conventional process, the surface of the substrate isembossed prior to the coating is applied. Thereby, the coating may fillless deep structures in the substrate and the visual impression of theembossing may be less distinguishable.

It has further been shown that pressing the coating layer may reduce anydamages, such as scratches, in the surface of the substrate. Suchscratches may be formed during the production and during handling underthe production process.

Applying pressure may comprise pressing the coating composition againsta pressing device comprising portions having different gloss levels,such that the coating layer obtains different gloss levels afterpressing. By applying the coating composition prior to pressing andthereafter pressing against a pressing device having portions withdifferent gloss levels, it is possible to obtain different gloss levelsin the coating layer in a simplified way compared to solutions known inthe art.

Applying pressure to the coating layer with the pressing device maycomprise applying heat and pressure simultaneously.

Applying pressure to the coating layer with the pressing device maycomprise bonding the substrate, said at least on one surface layer andthe coating composition together.

The coating composition may comprise a cross-linkable component. In across-linkable coating system, curing the coating composition crosslinksthe polymer.

The coating composition may comprise a residual oligomer content of lessthan 10% after curing Having some residual oligomer content correspondswith having some remaining crosslinking capacity. By some crosslinkingcapacity of the coating composition remaining after curing, theremaining crosslinking capacity facilitating that the coating layer maybe pressed after curing.

After curing the coating composition, e.g., such that the residualoligomer content is less than 10%, the coating composition is no longersticky. Thereby, the coated carrier may be handled, such as being rolledon a roller. By curing is meant that the coating composition has passedits pre-dried and/or pre-gelled state, e.g. having a residual oligomercontent being less than 10%.

The coating composition may be water-based. It has been discovered thata water based coating composition maintains capability to be re-shapedafter curing, thus facilitating the coating layer to be shaped duringpressing, for example, be embossed or be provided with a gloss level.

The coating composition may comprise a two-component system. Thetwo-component system may comprise an epoxy amine, a polyurethaneisocyanate, an isocyanate alcohol, or an acid alcohol system. Thecoating composition may be epoxy amine, polyurethane isocyanate,isocyanate alcohol, acid alcohol system. The coating composition may bea water-based two-component system.

The coating composition may be UV-curable, preferably a water-based UVcurable coating composition. By the coating composition being UV-curableis meant that at least a component of the coating composition isUV-curable. By using a UV curable composition, curing may be performedat a higher speed compared to pure water-based coating systems. Duringpressing, a cured UV cured coating layer does not stick to the pressplate. The surface of the coating may be harder compared to a sinteredcoating composition. The UV curable component may be apolyester/polyurethane dispersion. The UV curable component may be apolyurethane/acrylic copolymer dispersion.

Prior to pressing, a water-based UV-curable coating composition is firstcompletely dried in order to have the water to evaporate, and thereafterUV-cured, such that UV-curable components are cured. After being driedand UV-cured, the coating layer formed by the coating composition ispressed.

Said at least one surface layer may comprise a thermoplastic material,preferably PVC.

Said at least one surface layer may comprise a foil.

Said at least one surface layer may comprise a thermoplastic foil. Thethermoplastic foil may be PVC foil. The thermoplastic foil may be a wearresistant foil. The thermoplastic foil may be a decorative thermoplasticfoil, such as a printed thermoplastic foil. Thereby, a coatedthermoplastic foil may be formed, which may be pressed to a substrate insubsequent step. Since the coating layer is cured and pressed, thecoated wear resistant or decorative foil may be stored and handled as aconventional wear resistant foil.

Said at least one surface layer may comprise a wood-based substrate,preferably wood veneer. In one embodiment, a wood-based substrate iscoated and thereafter pressed. Thereby, the coating layer may, forexample, obtain an embossed structure by pressing against an embossedpressing device, and/or obtain different gloss levels by pressingagainst a pressing device having portions with different gloss levels.

Said at least one surface layer may comprise a paper, such as adecorative paper.

The coating composition may comprise scratch resistant particles, suchas silica particles. Thereby, the wear resistance of the coating layercan be improved. The coating composition may also include wear resistantparticles, such as aluminium oxide particles, also known as corundum.

Said at least one surface layer may comprise a first thermoplastic foiland a second thermoplastic foil, wherein wear resistant particles,preferably aluminium oxide particles, are arranged between the first andthe second foil. The first and second foils, with the wear resistantparticles therebetween, may be pre-pressed to be adhered to each other,prior or after the coating composition has been applied. Thereby, thecoated surface layer forms a wear resistant layer, which can be storedand handled as a separate layer, which may be pressed to a substrate ina subsequent step.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

The substrate may comprise a plastic board, such as a thermoplasticboard. The substrate may comprise a wood-based board. The wood-basedboard may be or comprise a wood veneer. The wood-based board may be orfurther comprise a wood fibre based board, such as MDF, HDF,particleboard etc., or a plywood board. The substrate may comprise orfurther comprise a wooden board, such as a lamella core. In embodiments,the substrate may comprise or further comprise thermoplastic board, forexample a Wood Plastic Composite (WPC), EPC (Expanded Polymer Core), orSPC (Stone Plastic Composite/Solid Polymer Core). The substrate maycomprise or further comprise a mineral composite board. The substratemay comprise or further comprise a fibre cement board. The substrate maycomprise or further comprise magnesium oxide cement board. The substratemay comprise or further comprise a ceramic board.

The substrate may comprise a paper or non-woven. The substrate may be aprinted paper. The substrate may comprise a laminate comprising athermosetting resin.

In one embodiment, the carrier comprises a thermoplastic material andthe substrate comprises a thermoplastic material of the above describedtype.

In one embodiment, the carrier comprises a thermoplastic material andthe substrate comprises a veneer. The veneer may be arranged on a boardof the above described type.

In one embodiment, the carrier comprises a thermoplastic material andthe substrate comprises a paper. The paper may be arranged on a board ofthe above described type.

In one embodiment, the carrier comprises a thermoplastic material andthe substrate is formed of a powder mix comprising a binder and fillers.The substrate may be arranged on a board of the above described type.The board may be a water-resistant board.

According to a third aspect, a building panel is provided. The buildingpanel comprises a substrate and at least one surface layer arranged onthe surface layer, wherein an uppermost surface layer is provided with acured coating layer.

The cured coating layer may comprise different gloss levels. Thedifferent gloss levels may be obtained by a pressing device after curingthe coating layer.

The cured coating layer may comprise an embossed structure. The embossedstructure may be obtained by a pressing device after curing the coatinglayer.

Embodiments of the third aspect may incorporate all the advantages ofthe second aspect, which previously has been discussed, whereby theprevious discussion is applicable also for the building panel.

The coating layer may be cross-linked. The coating layer may comprise across-linkable component. In a cross-linkable coating system, curing thecoating composition crosslinks the polymer.

The coating layer may be water-based, preferably a water-based UVcurable coating composition. It has been discovered that a water basedcoating composition maintains capability to be re-shaped after curing,thus facilitating the coating layer to be shaped during pressing, forexample, be embossed or be provided with a gloss level.

The coating layer may comprise a two-component system. The two componentsystem may be an epoxy amine, a polyurethane isocyanate, an isocyanatealcohol, or an acid alcohol system. The coating composition may be anepoxy amine, a polyurethane isocyanate, an isocyanate alcohol, or anacid alcohol system. The coating layer may be a water-basedtwo-component system.

The coating layer may be UV-cured, preferably be a water-based UV curedcoating layer. By the coating layer being UV-cured is meant that atleast a component of the coating composition is UV-cured. By using a UVcurable composition, curing may be performed at a higher speed comparedto pure water-based coating systems. During pressing, a cured UV curedcoating layer does not stick to the press plate. The surface of thecoating may be harder compared to a sintered coating composition. The UVcured component may be a polyester/polyurethane dispersion. The UV curedcomponent may be a polyurethane/acrylic copolymer dispersion.

Said at least one surface layer may comprise a thermoplastic material,preferably PVC.

Said at least one surface layer may comprise a foil.

Said at least one surface layer may comprise a thermoplastic foil. Thethermoplastic foil may be a PVC foil. The thermoplastic foil may be awear resistant foil. The thermoplastic foil may be a decorativethermoplastic foil, such as a printed thermoplastic foil.

The surface layer may be a wood-based substrate, preferably wood veneer.In one embodiment, a wood-based substrate is coated and thereafterpressed. Thereby, the coating layer may, for example, be provided anembossed structure by pressing against an embossed pressing device,and/or obtain different gloss levels by pressing against a pressingdevice having portions with different gloss levels.

The coating layer may comprise scratch resistant particles, such assilica particles. Thereby, the scratch resistance of the coating layercan be improved. The coating layer may also include wear resistantparticles, preferably aluminium oxide particles, also known as corundum.

Said at least one surface layer may comprise a first thermoplastic foiland a second thermoplastic foil, wherein wear resistant particles, suchas aluminium oxide particles, are arranged between the first and thesecond foil.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

The substrate may comprise a plastic board, such as a thermoplasticboard. The substrate may comprise a wood-based board. The wood-basedboard may be or comprise a wood veneer. The wood-based board may be orcomprise a wood fibre based board, such as MDF, HDF, particleboard,etc., or a plywood board. The substrate may comprise or further comprisea wooden board, such as a lamella core. In embodiments, the substratemay comprise or further comprise a thermoplastic board, for example aWood Plastic Composite (WPC), Expanded Polymer Core (EPC), Stone PlasticComposite (SPC), or Solid Polymer Core (SPC). The substrate may compriseor further comprise a mineral composite board. The substrate maycomprise or further comprise a fibre cement board. The substrate may bemagnesium oxide cement board. The substrate may comprise or furthercomprise a ceramic board.

The substrate may comprise a paper or non-woven. The substrate may be aprinted paper. The substrate may be formed of a powder mix comprising abinder and filler pressed to a surface layer.

According to a fourth aspect, a coated foil is provided. The coated foilcomprises a carrier and a cured coating layer arranged on a surface ofthe carrier.

The cured coating layer may comprise an embossed structure. The embossedstructure may be obtained by a pressing device after curing.

The cured coating layer may comprise different gloss levels. Thedifferent gloss levels may be obtained by a pressing device aftercuring.

Embodiments of the fourth aspect of the present invention incorporatesall the advantages of the first aspect of the invention, whichpreviously has been discussed, whereby the previous discussion isapplicable also for the coated foil.

The coating layer may be cross-linked.

The coating layer may be a UV-cured coating layer, preferably awater-based UV cured coating layer. By the coating layer being UV-curedis meant that at least a component of the coating composition isUV-cured. By using a UV curable composition, curing may be performed ata higher speed compared to pure water-based coating systems. Duringpressing, a cured UV cured coating layer does not stick to the pressplate. The surface of the coating may be harder compared to a sinteredcoating composition. The UV cured component may be apolyester/polyurethane dispersion. The UV cured component may be apolyurethane/acrylic copolymer dispersion.

The coating layer may comprise a two-component system. The coating layermay comprise an epoxy amine, a polyurethane isocyanate, an isocyanatealcohol, or an acid alcohol system. The coating layer may be awater-based two-component system.

The carrier may comprise thermoplastic material. The carrier may be afoil, such as a thermoplastic foil.

The coating layer may comprise scratch resistant particles, such assilica particles. Thereby, the scratch resistance of the coating layercan be further improved. The coating layer may also include wearresistant particles, such as aluminium oxide particles, also known ascorundum.

The carrier may comprise a first thermoplastic foil and a secondthermoplastic foil with wear resistant particles arranged therebetween.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

The coating layer may comprise portions having different gloss levels.

According to a fifth aspect, a method to produce a coated foil isprovided. The method comprises providing a first thermoplastic foil anda second thermoplastic foil, applying wear resistant particles on thefirst thermoplastic foil or on a second thermoplastic foil, applying thesecond thermoplastic foil on the first thermoplastic foil such that wearresistant particles are arranged between the first and secondthermoplastic foil, applying a coating composition on the secondthermoplastic foil, curing the coating composition such that a coatinglayer is formed, and subsequently applying pressure to the coatinglayer.

The coating is applied on a surface of the second foil facing away fromthe wear resistant particles.

By curing is meant completely curing or at least curing beyond apre-dried or pre-cured state.

An advantage of at least embodiments of the present invention is that byapplying the coating layer prior to pressing, the coating may beperformed inline, integrated with the assembling and adhering to otherlayers in, for example, a building panel. Thereby, a foil that isalready coated may be provided, requiring no additional surfacetreatment after the foil has been adhered to a substrate.

At least embodiments of the present invention allow that the coatinglayer may be handled as a separate layer after curing, and be adhered toanother substrate, etc., by pressing in a later operation.

A further advantage is that improved chemical resistance has shown to beachieved by pressing the coating layer. The improved chemical resistanceis believed to be achieved by the fact that the pressing furtherincreases the degree of crosslinking and/or by the compression of thecoating layer. By the higher degree of crosslinking, the higher chemicalresistance of the coating.

Furthermore, improved scratch resistance of the coating layer may beachieved, due to the higher degree of cross-linking obtained afterpressing, and/or due to the fact that the coating layer is compressed bythe pressing operation.

A further advantage is that by pressing the coating layer, also thecoating layer may be embossed by pressing against an embossed pressplate. In a conventional process, the surface of the substrate isembossed prior to the coating is applied. Thereby, the coating may fillless deep structures in the substrate and the visual impression of theembossing may be less distinguishable.

By including wear resistant particles between the first and secondfoils, the scratch resistant properties of the foils are improved, suchthat a coated foil having improved wear resistance is provided.

It has further been shown that pressing the coating layer may reduce anydamages, such as scratches in the coating layer. Such scratches may beformed during the production and during handling under the productionprocess.

Applying pressure may comprise pressing the coating layer against apressing device comprising portions having different gloss levels, suchthat the coating layer obtains different gloss levels after pressing. Byapplying the coating composition prior to pressing and thereafterpressing against a pressing device having portions with different glosslevels, it is possible to obtain different gloss levels in the coatinglayer in a simplified way compared to solutions known in the art.

The coating composition may comprise scratch resistant particles, suchas silica particles. Thereby, the scratch resistance of the coatinglayer can be further improved. The coating composition may also includewear resistant particles, such as aluminium oxide particles, also knownas corundum.

The coating composition may comprise a cross-linkable component. In across-linkable coating system, curing the coating composition crosslinksthe polymer.

The coating composition may have a residual oligomer content of lessthan 10% after curing. Having some residual oligomer content correspondswith having some remaining crosslinking capacity. By some crosslinkingcapacity of the coating composition remaining after curing, theremaining crosslinking capacity allows that the coating layer may bepressed after curing.

After curing the coating composition, the coating composition is nolonger sticky. Thereby, the coated carrier may be handled, such as beingrolled on a roller. By curing is meant that the coating composition haspassed its pre-dried and/or pre-gelled stadium.

The coating composition may be water-based, preferably a water-based UVcurable coating composition. It has been discovered that a water basedcoating composition maintains capability to be re-shaped after curing,thus facilitating the coating layer to be shaped during pressing, forexample, be embossed or be provided with a gloss level.

The coating composition may comprise a two-component system. The coatingcomposition may be an epoxy amine, a polyurethane isocyanate, anisocyanate alcohol, or an acid alcohol system. The coating compositionmay be an epoxy amine, a polyurethane isocyanate, an isocyanate alcohol,or an acid alcohol system. The coating composition may be a water-basedtwo-component system.

The coating composition may be UV-curable, preferably a water-based UVcurable coating composition. By the coating composition being UV-curableis meant that at least a component of the coating composition isUV-curable. By using a UV curable composition, curing may be performedat a higher speed compared to pure water-based coating systems. Duringpressing, a cured UV cured coating layer does not stick to the pressplate. The surface of the coating may be harder compared to a sinteredcoating composition. The UV curable component may be apolyester/polyurethane dispersion. The UV curable component may be apolyurethane/acrylic copolymer dispersion.

Applying pressure to the coating layer may comprise pressing andattaching the coating layer on the coated foil to a substrate. Thereby,a coated substrate, for example a building panel, may be provided,comprising a substrate and the coated foil. The coated foil may alreadybe provided with the coating layer prior to being adhered to thesubstrate. Thereby, the coated foil may be coated in process separatefrom handling the complete substrate.

The method may comprise applying pressure to the first and second foilprior to attaching the coated foil to the substrate, to adhere the firstand second foil to each other. This pre-pressing step may be performedprior or after applying the coating composition.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

The coating layer may comprise portions having different gloss levels.

According to a sixth aspect, a coated foil is provided. The coated foilcomprises a first thermoplastic foil and a second thermoplastic foilwith wear resistant particles arranged therebetween, wherein coatinglayer is arranged on a surface of the first thermoplastic foil facingaway from the second thermoplastic foil.

The coating layer may comprise different gloss levels obtained by apressing device.

The coating layer may comprise an embossed structure obtained by apressing device.

Embodiments of the sixth aspect of the present invention incorporatesall the advantages of the fifth aspect of the invention, whichpreviously has been discussed, whereby the previous discussion isapplicable also for the coated foil.

The coating layer may be cross-linked.

The coating layer may be a UV-cured coating layer, preferably awater-based UV cured coating layer.

The coating layer may comprise scratch resistant particles, such assilica particles. Thereby, the scratch resistance of the coating layercan be further improved. The coating layer may also include wearresistant particles, such as aluminium oxide particles, also known ascorundum.

The coating layer may be substantially transparent. The coating layermay be a layer conventionally referred to as a lacquer layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will by way of example be described in more detailwith reference to the appended schematic drawings, which showembodiments of the present invention.

FIG. 1A shows a method to produce a coated carrier.

FIG. 1B shows a method to produce a building panel.

FIG. 1C shows a method to produce a building panel.

FIG. 2 shows a method to produce a building panel.

FIG. 3 shows a method to produce a coated foil.

DETAILED DESCRIPTION

FIG. 1A shows a method to produce a coated carrier 10. A carrier 1 isprovided. The carrier 1 may be a release foil, for example afluoroplastic foil, or a permanent carrier, such as a thermoplasticfoil. The thermoplastic foil may comprise, for example, polyvinylchloride (PVC), polyurethane (PU), polyethylene terephthalate (PET),polyvinyl butyral (PVB), polybutylene terephthalate (PBT), cross-linkedpolyethylene (PEX), polyethylene (PE), polyester, polystyrene (PS),polypropylene (PP), polycarbonate (PC), polyvinyl acetate (PVAc),ethylene-vinyl acetate (EVA), polyacrylate, methacrylate, and/or acombination thereof. The thermoplastic material may comprise an ionomer,for example of polyethylene. The thermoplastic material may be a castingresin or hot melt. The carrier 1 may have thickness of 0.05-1 mm. Thethermoplastic foil may be printed and/or pigmented such that thethermoplastic foil forms a decorative foil.

In one embodiment, the carrier 1 is a wood veneer layer. The wood veneerlayer may have a thickness of about 0.2 to 1 mm. The wood veneer may bemade of any type of wood veneer. In one embodiment, the wood veneerlayer is an oak veneer layer.

A coating composition is applied on a surface of the carrier 1 by acoating device 20. The coating composition may be that beingtraditionally referred to as a lacquer. The coating composition may beapplied by roller coating, curtain coating, spraying, dip coating, etc.

The coating composition may be cross-linkable. The coating compositionmay be radiation curable, preferably UV curable. The coating compositionis preferably water-based, such as a UV curable water-based composition.The water-based UV curable composition may comprise apolyester/polyurethane dispersion. The water-based UV curablecomposition may comprise a polyurethane/acrylic copolymer dispersion.The water-based UV-curable composition may further comprise aphotoinitiator, thickener agent, additives, etc.

The coating composition may be a two-component system, such as an epoxyamine system, polyurethane isocyanate system, isocyanate alcohol system,acid alcohol system, etc.

The coating composition may be applied in one or several layers. Thetotal amount of the coating composition applied, converted to the amountcorresponding to 100% coating component and 0% water and solvent, may be5-200 g/m2, such as exceeding 5 g/m2, preferably exceeding 10 g/m2.

The coating composition may comprise wear resistant particles and/orscratch resistant particles. Preferably, the coating compositioncomprises scratch resistant particles. Alternatively or as a complement,scratch resistant particles may be applied on the coating compositionwhen on the carrier and when the coating composition still is wet.

The wear resistant particles may be aluminium oxide particles, such ascorundum. Alternatively, or as a complement, the wear resistantparticles may be carborundum, quartz, silica, glass, glass beads, glassspheres, diamond particles, hard plastics, reinforced polymers andorganics, or a combination thereof.

The wear resistant particles preferably have an average particle sizewithin the range of 10-200 μm, preferably within the range of 50-120 μm,such as 50-100 μm. The wear resistant particles may have a sphericalshape or an irregular shape. The wear resistant particles may be surfacetreated. The wear resistant particles may be silane-treated particles.The wear resistant particles may be applied in an amount of 10-100 g/m2,preferably in an amount of 10-50 g/m2, more preferably in an amount of20-30 g/m2.

The scratch resistant particles may be or comprise nano-sized silicaparticles, preferably fused silica particles. The scratch resistantparticles may be disc shaped particles, preferably having awidth/thickness ratio being equal or exceeding 3:1, more preferablybeing equal or exceeding 5:1. Such disc-shaped particles orientate alongthe surface of the foil, thereby improving the scratch resistance of thefoil. The scratch resistant particles may have an average particle sizeof 1-100 μm, preferably 10-50 μm, more preferably 20-30 μm. The scratchresistant particles may have an average particle size of less than 50μm, preferably less than 45 μm. The scratch resistant particles may beapplied in an amount of 0.5-20 g/m2, preferably in an amount of 0.5-10g/m2, more preferably in an amount of 0.5-5 g/m2.

The coating composition may comprise conventional additives. The coatingcomposition may further comprise functional additives, such as anti-statadditives and/or anti-bacterial additives.

The coating composition may be transparent. However, the coatingcomposition may also be pigmented.

The coating composition may be applied as one or several layers forminga coating on the carrier 1.

After the coating composition has been applied on the carrier 1, thecoating composition is cured such that a coating layer 2 is formed. Ifthe coating composition is UV curable, UV radiation is applied to curethe coating composition. If the coating composition is water-based UVcurable coating composition, the coating composition is first dried in adrying device 21 by IR or in an oven and thereafter is cured by applyingUV radiation to the coating in a UV radiation device 22. If the coatingcomposition is a two-component system, the coating composition is dried,for example, in an oven or in room temperature (not shown).

After curing, a coated carrier 10 is formed.

Preferably, some crosslinking capacity of the coating compositionremains after curing. The coating composition may have a residualoligomer content of less than 10% after curing. Having some residualoligomer content corresponds with having some remaining crosslinkingcapacity. Thereby, during pressing in a subsequent step, the coatingcomposition may be further crosslinked and/or compressed.

The coated carrier 10 formed by the method described with reference toFIG. 1A may be stored after the coating composition has been cured. Aswill be further described with reference to FIGS. 1B and 1C, the coatedcarrier 10 may be applied to a substrate, or wherein the carrier is arelease foil, the coating layer 2 may be applied to a substrate withoutthe carrier 1. The coated carrier 10 may be intended to be used ascoated wear resistant foil. In one embodiment, wherein the carrier isdecorative thermoplastic foil, the coated carrier 10 may be a coateddecorative foil.

In FIG. 1B, the coated carrier 10 formed as described above withreference to FIG. 1A is intended to form part of a building panel 5. Thebuilding panel 5 may be a floor panel, a wall panel, a ceiling panel, afurniture component, etc. For example, the building panel may be of thetype being known as LVT or WPC.

In the embodiment shown in FIG. 1B, the coated carrier 10 forms a coatedwear resistant foil in the building panel 5. In the embodiment shown inFIG. 1B, the coated wear resistant foil comprises a thermoplasticmaterial. The thermoplastic material may be polyvinyl chloride (PVC),polyurethane (PU), polyethylene terephthalate (PET), polyvinyl butyral(PVB), polybutylene terephthalate (PBT), cross-linked polyethylene(PEX), polyethylene (PE), polyester, polystyrene (PS), polypropylene(PP), polycarbonate (PC), polyvinyl acetate (PVAc), ethylene-vinylacetate (EVA), polyacrylate, methacrylate, and/or a combination thereof.The thermoplastic material may comprise an ionomer, for example ofpolyethylene. The thermoplastic material may be a casting resin or hotmelt. Preferably, the coating layer of the coated carrier 10 compriseswear and/or scratch resistant particles of the type described above,preferably scratch resistant particles of the type described.

In FIG. 1B, a substrate 3 is provided. The substrate may comprise athermoplastic material. The substrate 3 may comprise a thermoplasticmaterial and fillers, such as a WPC (Wood Plastic Composite), ExpandedPolymer Core (EPC), Stone Plastic Composite (SPC), or Solid Polymer Core(SPC), or any other type of a polymer core comprising fillers and athermoplastic material. The core may be extruded or calendered. Thethermoplastic material may comprise polyvinyl chloride (PVC),polyurethane (PU), polyethylene terephthalate (PET), polyvinyl butyral(PVB), polybutylene terephthalate (PBT), cross-linked polyethylene(PEX), polyethylene (PE), polyester, polystyrene (PS), polypropylene(PP), polycarbonate (PC), polyvinyl acetate (PVAc), ethylene-vinylacetate (EVA), polyacrylate, methacrylate, and/or a combination thereof.The thermoplastic material may comprise an ionomer, for example ofpolyethylene. The thermoplastic material may be a casting resin or hotmelt.

In other embodiments, the substrate 3 may comprise a wood-basedsubstrate, such as a wood veneer or may be or comprise a wood fibrebased board, such as MDF, HDF, particleboard etc., or a plywood board.In other embodiments, the substrate may comprise a paper, such as adecorative paper. In other embodiments, the substrate may be formed of adry powder mix comprising a binder and filler being pressed into asurface layer.

In the embodiment shown in FIG. 1B, a decorative layer 4 is provided andarranged on a surface of the substrate 3. It is also contemplated thatthe substrate 3 is provided with a decorative design, such as a print.In such an embodiment, the coated carrier 10 is arranged directly on asurface of the substrate 3 (not shown). It is also contemplated that thethermoplastic foil forming the carrier 1 of the coated carrier 10 isprovided with a decorative design, such as a print. In such anembodiment, the coated carrier 10 is arranged directly on a surface ofthe substrate 3 (not shown).

The decorative layer 4 may comprise a thermoplastic material. Thethermoplastic material may be polyvinyl chloride (PVC), polyurethane(PU), polyethylene terephthalate (PET), polyvinyl butyral (PVB),polybutylene terephthalate (PBT), cross-linked polyethylene (PEX),polyethylene (PE), polyester, polystyrene (PS), polypropylene (PP),polycarbonate (PC), polyvinyl acetate (PVAc), ethylene-vinyl acetate(EVA), polyacrylate, methacrylate, and/or a combination thereof. Thethermoplastic material may comprise an ionomer, for example ofpolyethylene. The thermoplastic material may be a casting resin or hotmelt. The decorative layer may be provided with a decorative design,such as a print.

In other embodiments, the decorative layer 4 may comprise a wood veneer,or a paper, such as a decorative paper.

The coated carrier 10 is arranged on the decorative layer 4. Inalternative embodiment, the coating layer may be released from thecarrier 1 in form of a release foil, and subsequently be arrangeddirectly on the decorative layer 4, or on the substrate 3.

In embodiments, an adhesive may be provided between the decorative layer4 and the substrate 3.

The substrate 3, the decorative layer 4, and the coated carrier 10 withthe cured coating layer 2 are thereafter pressed together in pressingdevice 23 such that the layers are adhered to each other and a buildingpanel 5 is formed. The pressing device 23 may be static or continuous.Preferably, heat is also applied during pressing. The pressure appliedmay be 5-100 bar, applied for example during 5-500 seconds. Thetemperature may be 80-300° C., such as 100-250° C., such as 120-180° C.,such as 130-150° C. The temperature may be about 140° C.

The pressing device 23 may have different gloss levels. A press surfaceof the pressing device 23 may have portions having high gloss, or evensuper high gloss levels and portions being matt. The different glosslevels are provided with micro embossings or a micros structure having amaximum depth of 30 μm. The higher depth of the micro structure, themore the portion or portions having a matt texture. The lower depth ofthe micro structure, the more glossy portion or portions. When pressingthe coated carrier 10 against the micro structure, the coated carrier 10obtains portions having different gloss levels. The depth of the microembossing may vary over the surface of the pressing device 23 such thata varying gloss levels are obtained. When pressing the coated carrier 10against the micro structure, the coated carrier 10 obtains portionshaving different gloss levels, corresponding to the gloss levels of thepress surface of the pressing device 23. The gloss levels may be varyingover the surface of the coated carrier 10. By different gloss levels ispreferably meant that the gloss level of a first portion, or a first setof portions, differs from the gloss level of a second portion, or asecond set of portions. The first portion, or the first set of portions,may have a higher gloss level than the second portion, or the second setof portions. The first portion, or first set of portions, may have afirst degree of gloss, and the second portion, or second set ofportions, may have a second degree of gloss, being higher or lower thanfirst degree of gloss.

The pressing device 23 may also be provided with protrusions for formingmacro embossings or a macro structure in the coating layer of the coatedcarrier. The macro structure may also be in register with the decorativeprint or printed design of the decorative layer.

The pressing device 23 may comprise a metal surface provided with thedifferent gloss levels as described above. The metal surface of thepressing device is adapted to directly contact the coating layer 2 ofthe coated carrier 10. The pressing device 23 may be a pressing cylinderor pressing plate provided with the different gloss levels, wherein thepressing cylinder or pressing plate directly contacts the surface of thecoated carrier 10.

In one embodiment, the pressing device 23 may comprise a structure foilprovided with different gloss levels. The structure foil is adapted todirectly contact the surface of the coated carrier. The structure foilmay be arranged between the coated carrier and a press plate, press beltor press cylinder during pressing.

The surface of the coated carrier 10 may be provided with a releaseagent in order to prevent that the coated carrier sticks to the pressingdevice during pressing at elevated pressing temperature. Since noadditional layer is to be applied on the coated carrier 10, a releaseagent can be applied on the coated carrier 10, thereby facilitating thepressing operation.

After pressing, the coated carrier 10 may have portions with differentgloss levels. The different gloss levels are formed by a micro structurein the coating layer, preferably having a maximum depth of 30 μm. Thedifferent gloss levels may be formed in register with the decorativepattern or printed design of the decorative layer 4.

The coating layer of the coated carrier 10 may also be provided withembossed portions during pressing. The pressing device 23, such as thepress plate, the press cylinder, the press belt or structure foil may beprovided with protrusions forming embossing or macro structure in thecoating layer of the coated carrier 10. Alternatively, the embossedportions may be formed in a separate step from forming the portionshaving different gloss levels. The embossing is preferably in registerwith the decorative pattern or printed design. The embossing ispreferably coordinated with the portions having different gloss levelsof the coated carrier 10. The embossed portions in the wear resistantlayer, preferably have a depth exceeding 100 μm.

By pressing the coated carrier 10 to the substrate 3, with an optionalintermediate decorative layer 4, a building panel 5 is formed.

In FIG. 1C, the coated carrier 10 formed as described above withreference to FIG. 1A is intended to form part of a building panel 5. Thebuilding panel 5 may be a floor panel, a wall panel, a ceiling panel, afurniture component, etc.

In the embodiment described with reference to FIG. 1C, the carrier 1 isa wood veneer layer. The wood veneer layer may have a thickness of about0.2 to 1 mm. The veneer may be made of any type of veneer. In oneembodiment, the wood veneer layer is an oak veneer layer. Consequently,a coated wood veneer layer 10 is formed by the process described abovewith reference to FIG. 1A.

In the embodiment shown in FIG. 1C, the coated wood veneer layer 10forms a surface of a building panel 5. In FIG. 1C, the coated woodveneer layer 10 is arranged on a substrate 3, and adhered to thesubstrate 3. The substrate 3 may be a wood-based board. The wood-basedboard may be a wood fibre based board, such as MDF, HDF, particleboardetc., or a plywood board. The substrate 3 may be a wooden board, such asa lamella core. In other embodiments, the substrate may be athermoplastic board, for example a Wood Plastic Composite (WPC),Expanded Polymer Core (EPC), Stone Plastic Composite (SPC), or SolidPolymer Core (SPC). The substrate 3 may be a mineral composite board.The substrate may be a fibre cement board. The substrate 3 may bemagnesium oxide cement board. The substrate may be a ceramic board. Thesubstrate 3 may be a plastic board, such as a thermoplastic board. Inother embodiments, the substrate 3 may be a carrier, such as sheet ofpaper or non-woven. The wood-based substrate 3 may be printed,preferably by digital printer.

The coated wood veneer layer 10 with the cured coating layer 2 ispressed in a pressing device 23, preferably simultaneously as beingadhered to the substrate. The coated wood veneer layer 10 may be adheredto the substrate 3 under pressure. An adhesive layer may be applied onthe coated wood veneer layer 10 and/or the substrate 3. The adhesivelayer may comprise a thermoplastic binder. The thermoplastic binder maybe polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP),polyurethane (PU), polyvinyl alcohol (PVOH), polyvinyl butyral (PVB),and/or polyvinyl acetate (PVAc), or a combination thereof. The adhesivelayer may comprise a hot melt or pressure sensitive adhesive.

The pressing device 23 may be static or continuous. Preferably, heat isalso applied. The pressure applied may be 5-100 bar, applied for exampleduring 5-500 seconds. The temperature may be 80-300° C., such as100-250° C., such as 120-180° C., such as 130-150° C. The temperaturemay be about 140° C.

The pressing device 23 may have different gloss levels. A press surfaceof the pressing device 23 may have portions having high gloss, or evensuper high gloss levels and portions being matt. The different glosslevels are provided with micro embossings or a micros structure having amaximum depth of 30 μm. The higher depth of the micro structure, themore the portion or portions having a matt texture. The lower depth ofthe micro structure, the more glossy portion or portions. When pressingthe coated wood veneer layer 10 against the micro structure, the coatedwood veneer layer 10 obtains portions having different gloss levels. Thedepth of the micro embossing may vary over the surface of the pressingdevice 23 such that a varying gloss levels are obtained. When pressingthe coated wood veneer layer 10 against the micro structure, the coatedwood veneer layer 10 obtains portions having different gloss levels,corresponding to the gloss levels of the press surface of the pressingdevice 23. The gloss levels may be varying over the surface of thecoated wood veneer layer 10. By different gloss levels is preferablymeant that the gloss level of a first portion, or a first set ofportions, differs from the gloss level of a second portion, or a secondset of portions. The first portion, or the first set of portions, mayhave a higher gloss level than the second portion, or the second set ofportions. The first portion, or first set of portions, may have a firstdegree of gloss, and the second portion, or second set of portions, mayhave a second degree of gloss, being higher or lower than first degreeof gloss.

The pressing device 23 may also be provided with protrusions for formingmacro embossings or a macro structure of the coating layer of the coatedwood veneer layer 10. The macro structure may also be in register withthe wood pattern of the coated wood veneer layer 10.

The pressing device 23 may comprise a metal surface provided with thedifferent gloss levels as described above. The metal surface of thepressing device 23 is adapted to directly contact the surface of thecoated carrier. The pressing device 23 may be a pressing cylinder orpressing plate provided with the different gloss levels, wherein thepressing cylinder or pressing plate directly contacts the surface of thecoated carrier.

In one embodiment, the pressing device 23 may comprise a structure foilprovided with different gloss levels. The structure foil is adapted todirectly contact the surface of the coated wood veneer layer 10. Thestructure foil may be arranged between the coated wood veneer layer 10and a press plate, press belt or press cylinder during pressing.

The surface of the coated wood veneer layer 10 may be provided with arelease agent in order to avoid that the coated carrier sticks to thepressing device 23. Since no additional layer is to be applied on thecoated wood veneer layer 10, a release agent can be applied on thecoated wood veneer layer 10, thereby facilitating the pressingoperation.

After pressing, the coated wood veneer layer 10 may have portions withdifferent gloss levels. The different gloss levels are formed by a microstructure in the surface, preferably having a maximum depth of 30 μm.The different gloss levels may be formed in register with the woodpattern of the coated wood veneer layer 10.

The surface of the coated wood veneer layer 10 may also be provided withembossed portions during pressing. The pressing device 23, such as thepress plate, the press cylinder, the press belt or structure foil may beprovided with protrusions forming embossing or macro structure in thecoated wood veneer layer 10. Alternatively, the embossed portions may beformed in a separate step from forming the portions having differentgloss levels. The embossing is preferably in register with the woodpattern. The embossing is preferably coordinated with the portionshaving different gloss levels of the coated wood veneer layer 10. Theembossed portions in the wear resistant layer, preferably have a depthexceeding 100 μm.

Thereby, a building panel 5 is formed, comprising the coated wood veneerlayer 10 adhered to the substrate 3.

In the embodiment described with reference to FIG. 1C, as alternative toa wood veneer layer, the carrier 1 may comprise a paper, such as adecorative paper.

In FIG. 2, an integrated method of forming a coated building panel 5 isshown. In FIG. 2, a substrate 3 and at least one surface layer isprovided. In the embodiment shown in FIG. 2, the surface layer comprisesa decorative layer 4 and a carrier 1.

The substrate 3 may comprise a thermoplastic material. The substrate 3may comprise a thermoplastic material and fillers, such as WPC (WoodPlastic Composite), EPC (Expanded Polymer Core), or SPC (Stone PlasticComposite/Solid Polymer Core), or any other type of a polymer corecomprising fillers and a thermoplastic material. The substrate may beextruded or calendered. The thermoplastic material of may comprisepolyvinyl chloride (PVC), polyurethane (PU), polyethylene terephthalate(PET), polyvinyl butyral (PVB), polybutylene terephthalate (PBT),cross-linked polyethylene (PEX), polyethylene (PE), polyester,polystyrene (PS), polypropylene (PP), polycarbonate (PC), polyvinylacetate (PVAc), ethylene-vinyl acetate (EVA), polyacrylate,methacrylate, and/or a combination thereof. The thermoplastic materialmay comprise an ionomer, for example of polyethylene. The thermoplasticmaterial may be a casting resin or hot melt.

In one embodiment, the substrate 3 may comprise a wood-based board. Thewood-based board may be a wood fibre based board, such as MDF, HDF,particleboard, etc., or a plywood board. The substrate 3 may be a woodenboard, such as a lamella core. In other embodiments, the substrate 3 maybe a thermoplastic board, for example a Wood Plastic Composite (WPC),EPC (Expanded Polymer Core), or SPC (Stone Plastic Composite/SolidPolymer Core). The substrate 3 may be a mineral composite board. Thesubstrate 3 may be a fibre cement board. The substrate 3 may bemagnesium oxide cement board. The substrate 3 may be a ceramic board.The substrate 3 may be a plastic board, such as a thermoplastic board.In other embodiments, the substrate 3 may be a carrier, such as sheet ofpaper or non-woven.

The decorative layer 4 may comprise a thermoplastic material. Thethermoplastic material may be polyvinyl chloride (PVC), polyurethane(PU), polyethylene terephthalate (PET), polyvinyl butyral (PVB),polybutylene terephthalate (PBT), cross-linked polyethylene (PEX),polyethylene (PE), polyester, polystyrene (PS), polypropylene (PP),polycarbonate (PC), polyvinyl acetate (PVAc), ethylene-vinyl acetate(EVA), polyacrylate, methacrylate, and/or a combination thereof. Thethermoplastic material may comprise an ionomer, for example ofpolyethylene. The thermoplastic material may be a casting resin or hotmelt. The decorative layer may be provided with a decorative design,such as a print.

In other embodiments, the decorative layer 4 may comprise a wood veneer,or a paper, such as a decorative paper. It is also contemplated that thesubstrate 3 is provided with a decorative design, such as a print. Insuch an embodiment, the carrier 1 is arranged directly on a surface ofthe substrate 3. It is also contemplated that the carrier 1 of thecoated carrier 10 is provided with a decorative design, such as a print.In such an embodiment, the carrier 1 is arranged directly on a surfaceof the substrate 3.

The carrier 1 may be a thermoplastic foil. The thermoplastic foil maycomprise, for example, polyvinyl chloride (PVC), polyurethane (PU),polyethylene terephthalate (PET), polyvinyl butyral (PVB), polybutyleneterephthalate (PBT), cross-linked polyethylene (PEX), polyethylene (PE),polyester, polystyrene (PS), polypropylene (PP), polycarbonate (PC),polyvinyl acetate (PVAc), ethylene-vinyl acetate (EVA), polyacrylate,methacrylate, and/or a combination thereof. The thermoplastic materialmay comprise an ionomer, for example of polyethylene. The thermoplasticmaterial may be a casting resin or hot melt. The carrier 1 may havethickness of 0.05-1 mm. The thermoplastic foil may be printed and/orpigmented such that the thermoplastic foil forms a decorative foil.

A coating composition is applied on a surface of the carrier 1 by acoating device 20. The coating composition may be that beingtraditionally referred to as a lacquer. The coating composition may beapplied by roller coating, curtain coating, dip coating, spraying, etc.

The coating composition is cross-linkable. The coating composition maybe radiation curable, preferably UV curable. The coating composition ispreferably water-based, such as a UV curable water-based composition.The water-based UV curable composition may comprise apolyester/polyurethane dispersion. The water-based UV curablecomposition may comprise a polyurethane/acrylic copolymer dispersion.The water-based UV-curable composition may further comprise aphotoinitiator, thickener agent, additives etc.

The coating composition may be a two-component system, such as an epoxyamine system, polyurethane isocyanate system, isocyanate alcohol system,acid alcohol system, etc.

The coating composition may be applied in one or several layers. Thetotal amount of the coating composition applied, converted to the amountcorresponding to 100% coating component and 0% water and solvent, may be5-200 g/m2, such as exceeding 5 g/m2, preferably exceeding 10 g/m2.

The coating composition may comprise wear resistant particles and/orscratch resistant particles. Preferably, the coating compositioncomprises scratch resistant particles. Alternatively, or as acomplement, scratch resistant particles may be applied on the coatingcomposition applied on the carrier when the coating composition still iswet.

The wear resistant particles may be aluminium oxide particles, such ascorundum. Alternatively, or as a complement, the wear resistantparticles may be carborundum, quartz, silica, glass, glass beads, glassspheres, diamond particles, hard plastics, reinforced polymers andorganics, or a combination thereof.

The wear resistant particles preferably have an average particle sizewithin the range of 10-200 μm, preferably within the range of 50-120 μm,such as 50-100 μm. The wear resistant particles may have a sphericalshape or an irregular shape. The wear resistant particles may be surfacetreated. The wear resistant particles may be silane-treated particles.The wear resistant particles may be applied in an amount of 10-100 g/m2,preferably in an amount of 10-50 g/m2, more preferably in an amount of20-30 g/m2.

The scratch resistant particles may be or comprise nano-sized silicaparticles, preferably fused silica particles. The scratch resistantparticles may be disc shaped particles, preferably having awidth/thickness ratio being equal or exceeding 3:1, more preferablybeing equal or exceeding 5:1. Such disc-shaped particles orientate alongthe surface of the foil, thereby improving the scratch resistance of thefoil. The scratch resistant particles may have an average particle sizeof 1-100 μm, preferably 10-50 μm, more preferably 20-30 μm. The scratchresistant particles may have an average particle size of less than 50μm, preferably less than 45 μm. The scratch resistant particles may beapplied in an amount of 0.5-20 g/m2, preferably in an amount of 0.5-10g/m2, more preferably in an amount of 0.5-5 g/m2.

The coating composition may comprise conventional additives. The coatingcomposition may further comprise may be functional additives, such asanti-stat additives and/or anti-bacterial additives.

The coating composition may be transparent. However, the coatingcomposition may also be pigmented.

The coating composition may be applied as one or several layers on thecarrier 1.

After the coating composition has been applied on the carrier 1, thecoating composition is cured such that a coating layer 2 is formed. Ifthe coating composition is UV curable, UV radiation is applied to curethe coating composition. If the coating composition is water-based UVcurable coating composition, the coating composition is first dried in adrying device 21 by IR or in an oven and thereafter is cured by applyingUV radiation to the coating composition in UV radiation device 22. Ifthe coating composition is a two-component system, the coatingcomposition is dried, for example, in an oven or in room temperature.

After curing, a coated carrier 10 is formed.

Preferably, some crosslinking capacity of the coating compositionremains after curing. The coating composition may have a residualoligomer content of less than 10% after curingHaving some residualoligomer content corresponds with having some remaining crosslinkingcapacity. Thereby, during pressing in a subsequent step, the coatingcomposition may be further crosslinked.

In the embodiment shown in FIG. 2, the substrate, the decorative layer 4and the coated carrier 10 with the cured coating layer 2 are pressedtogether in line with the coating step in a pressing device 23.Preferably, the pressing device 23 is continuous. Preferably, heat isalso applied. The pressure applied may be 5-100 bar, applied for exampleduring 5-500 seconds. The temperature may be 80-300° C., such as100-250° C., such as 120-180° C., such as 130-150° C. The temperaturemay be about 140° C.

The pressing device 23 may have different gloss levels. A press surfaceof the pressing device 23 may have portions having high gloss, or evensuper high gloss levels and portions being matt. The different glosslevels are provided with micro embossings or a micros structure having amaximum depth of 30 μm. The higher depth of the micro structure, themore the portion or portions having a matt texture. The lower depth ofthe micro structure, the more glossy portion or portions. When pressingthe coating layer 2 against the micro structure, the coating layer 2obtains portions having different gloss levels. The depth of the microembossing may vary over the surface of the pressing device 23 such thata varying gloss levels are obtained. When pressing the coating layer 2against the micro structure, the coating layer 2 obtains portions havingdifferent gloss levels, corresponding to the gloss levels of the presssurface of the pressing device 23. The gloss levels may be varying overthe surface of the coating layer 2. By different gloss levels ispreferably meant that the gloss level of a first portion, or a first setof portions, differs from the gloss level of a second portion, or asecond set of portions. The first portion, or the first set of portions,may have a higher gloss level than the second portion, or the second setof portions. The first portion, or first set of portions, may have afirst degree of gloss, and the second portion, or second set ofportions, may have a second degree of gloss, being higher or lower thanfirst degree of gloss.

The pressing device 23 may also be provided with protrusions for formingmacro embossings or a macro structure of the surface of the coatedcarrier 10. The macro structure may also be in register with thedecorative print or printed design of the decorative layer 4.

The pressing device 23 may comprise a metal surface provided with thedifferent gloss levels as described above. The metal surface of thepressing device 23 is adapted to directly contact the surface of thecoating layer 2. The pressing device 23 may be a pressing cylinder orpressing plate provided with the different gloss levels, wherein thepressing cylinder or pressing plate directly contacts the surface of thecoated carrier 10.

In one embodiment, the pressing device 23 may comprise a structure foilprovided with different gloss levels. The structure foil is adapted todirectly contact the surface of the coating layer 2. The structure foilmay be arranged between the coating layer 2 and a press plate, pressbelt or press cylinder during pressing.

The coating layer 2 may be provided with a release agent in order toavoid that the coating layer 2 sticks to the pressing device. Since noadditional layer is to be applied on the coating layer 2, a releaseagent can be applied on the coating layer 2, thereby facilitating thepressing operation.

After pressing, the coating layer 2 may have portions with differentgloss levels. The different gloss levels are formed by a micro structurein the surface, preferably having a maximum depth of 30 μm. Thedifferent gloss levels may be formed in register with the decorativepattern or printed design of the decorative layer.

The coating layer 2 may also be provided with embossed portions duringpressing. The pressing device 23, such as the press plate, the presscylinder, the press belt or structure foil, may be provided withprotrusions forming embossing or macro structure in the coating layer 2.Alternatively, the embossed portions may be formed in a separate stepfrom forming the portions having different gloss levels. The embossingis preferably in register with the decorative pattern or printed design.The embossing is preferably coordinated with the portions havingdifferent gloss levels of the coated carrier. The embossed portions inthe wear resistant layer, preferably have a depth exceeding 100 μm.

By pressing the coated carrier 10 to the substrate 3, with an optionalintermediate decorative layer 4, a building panel 5 is formed.

In FIG. 3, an alternative method of forming a coated foil 10′ is shown.The coated foil 10′ comprises in this embodiment a first foil 8 and asecond foil 9.

The first foil 8 comprises a first thermoplastic material. The firstthermoplastic material may be polyvinyl chloride (PVC), polyester,polypropylene (PP), polyethylene (PE), polystyrene (PS), polyurethane(PU), polyethylene terephthalate (PET), polyacrylate, methacrylate,polycarbonate, polyvinyl butyral, polybutylene terephthalate, or acombination thereof.

Preferably, the first foil 8 is formed of the thermoplastic material.The first foil 8 may substantially consist of the thermoplasticmaterial, and optionally additives. Additives may be plasticizers,stabilizers, lubricants, degassing agents, coupling agents,compatibilizers, crosslinking agents, etc.

In one embodiment, the first foil 1 is a PVC foil.

The first foil 8 may have a thickness of 0.1-1 mm. Preferably, the firstfoil 8 has a thickness less than 0.5 mm, more preferably about 100 μm,preferably as measured in the final product, for example, afterpressing. The first foil 8 may be a decorative foil.

Wear resistant particles 6 may be applied on the first foil 8 by ascattering device 24. The wear resistant particles may be aluminiumoxide particles, such as corundum. Alternatively, or as a complement,the wear resistant particles 6 may be carborundum, quartz, silica,glass, glass beads, glass spheres, diamond particles, hard plastics,reinforced polymers and organics, or a combination thereof.

The wear resistant particles 6 preferably have an average particle sizewithin the range of 10-200 μm, preferably within the range of 50-120 μm,such as 50-100 μm. The wear resistant particles 6 may have an averageparticle size of less than 50 μm, preferably less than 45 μm. The wearresistant particles 6 may have a spherical shape or an irregular shape.The wear resistant particles 6 may be surface treated. The wearresistant particles 6 may be silane-treated particles.

The wear resistant particles 6 may have a refractive index similar tothe refractive index of the second foil. The wear resistant particles 6may have a refractive index of 1.4-1.9. In one embodiment, the wearresistant particle may have a refractive index of 1.4-1.9, preferably1.5-1.8, for example, 1.7-1.8. In an embodiment, the refractive index ofthe wear resistant particles 6 may not differ from the refractive indexof the second foil more than ±20%.

The wear resistant particles 6 may be applied in an amount of 10-100g/m2, preferably in an amount of 10-50 g/m2, more preferably in anamount of 20-30 g/m2. After the wear resistant particles 6 have beenapplied on the first foil 8, a second foil 9 is provided and arranged onthe first foil 9. The wear resistant particles 6 are therebyencapsulated by the first foil 8 and the second foil 9.

As an alternative or complement to apply the wear resistant particles 6on the first foil 8, the wear resistant particles may be applied on thesecond foil 9. In this embodiment, the second foil 9 with the wearresistant particles 6 is arranged on the first foil 8, or vice versa.

The second foil 9 comprises a second thermoplastic material. The secondthermoplastic material may be the same as in the first foil 8, or beingdifferent from the thermoplastic material of the first foil 8. Thesecond thermoplastic may be polyvinyl chloride (PVC), polyester,polypropylene (PP), polyethylene (PE), polystyrene (PS), polyurethane(PU), polyethylene terephthalate (PET), polyacrylate, methacrylate,polycarbonate, polyvinyl butyral, polybutylene terephthalate, or acombination thereof.

Preferably, the second foil 9 is formed of the thermoplastic material.The second foil may substantially consist of the thermoplastic material,and optionally additives. Additives may be plasticizers, stabilizers,lubricants, degassing agents, coupling agents, compatibilizers,crosslinking agents, etc.

In one embodiment, the first foil 8 is a PVC foil and the second foil 9is PU foil.

The second foil 9 may be provided as a foil produced in a separateproduction step. The second foil 9 may be provided as continuous web.

In other embodiments, the second foil 9 may be formed by an extrusionprocess, such as extrusion coating or extrusion lamination of the secondfoil 9 on the first foil 8.

The second foil 9 may have a thickness of 0.01-1 mm. Preferably, thesecond foil 9 has a thickness less than 0.5 mm, more preferably about90-110 μm, e.g., 100 μm, preferably as measured in the final product,for example, after pressing. In an embodiment wherein the second foil isa PVC foil, the thickness may be about 100 μm. In an embodiment whereinthe second foil is a PU foil, the thickness may be about 40-60 μm, e.g.,50 μm.

The first foil 8 may have a thickness exceeding the thickness of thesecond foil 9. Especially if the first foil 8 comprises PVC and thesecond foil 9 comprises PU, the first foil 8 may have a thicknessexceeding the thickness of the second foil 9.

The wear resistant particles 6 may have an average particle size beingless than the thickness of the second foil 9. However, the wearresistant particles 6 may have an average particle size being largerthan the thickness of the second foil 9. During pressing, the wearresistant particles 6 are pressed into the first foil 8 such that thewear resistant particles do not protrude beyond an upper surface of thesecond foil 9 after pressing, although the wear resistant particles 6have an average particle size exceeding the thickness of the second foil9.

The first and the second foil 8, 9 are thereafter adhered to each otherto form a wear resistant foil 1′ comprising the first foil 8, the secondfoil 9, and wherein at least a part of the wear resistant particles arearranged between the first foil and the second foil.

The wear resistant foil 1′ is preferably transparent, or at leastsubstantially transparent.

The first and the second foil 8, 9 may be adhered to each other by beingpressed together, for example, in a calendering/laminating process. Asshown in FIG. 3, the first and the second foil 8, 9 are pressed in acontinuous press 25. The first and second foil 8, 9 may be adheredtogether by pressure alone, by heat and pressure, by pressure andadhesive, or by heat, pressure, and adhesive. Preferably, both pressureand heat are applied in order to adhere the first and the second foil toeach other. As alternative or complements to a calendering process, acontinuous or static press may also be used. The pressing operation may,for example, be a hot-hot process, a hot-cold process, etc. The pressingmay be made with an embossed press matrix or press roller, such that anembossed structure is formed in the wear resistant foil 1′.

Depending on the thermoplastic materials and process used, the pressureapplied may be 5-100 bar, applied, for example, during 5-500 seconds.The temperature may be 80-300° C., such as 100-250° C., such as 120-180°C., such as 130-150° C. The temperature may be about 140° C.

After adhering, for example, by pressing, the layers to each other, thewear resistant particles 6 are enclosed by the first and the second foil8, 9. Preferably, the wear resistant particles are completely enclosedby the first and the second foils 8, 9. Preferably, the wear resistantparticles do not protrude beyond the surface of the second foil 9 facingaway from the first foil 8. Thereby, a wear resistant foil 1′ having asmooth surface can be formed.

As described above with reference to FIG. 1A, the wear resistant foil 1′forming a carrier, formed by the first and second foil 8, 9 is coated bya coating composition being applied on a surface of the second foil 9.The coating composition may be that being traditionally referred to as alacquer. The coating composition may be applied by roller coating,curtain coating, dip coating, spraying, etc.

The coating composition is cross-linkable. The coating composition maybe radiation curable, preferably UV curable. The coating composition ispreferably water-based, such as a UV curable water-based composition.The water-based UV curable composition may comprise apolyester/polyurethane dispersion. The water-based UV curablecomposition may comprise a polyurethane/acrylic copolymer dispersion.The water-based UV-curable composition may further comprise aphotoinitiator, thickener agent, additives etc.

The coating composition may be a two-component system, such as an epoxyamine system, polyurethane isocyanate system, isocyanate alcohol system,acid alcohol system, etc.

The coating composition may be applied in one or several layers. Thetotal amount of the coating composition applied, converted to the amountcorresponding to 100% coating component and 0% solvent, may be 5-200g/m2, such as exceeding 5 g/m2, preferably exceeding 10 g/m2.

The coating composition may comprise wear resistant particles and/orscratch resistant particles. Preferably, the coating compositioncomprises scratch resistant particles. Alternatively, or as acomplement, scratch resistant particles may be applied on the coatingcomposition applied on the carrier when the coating composition still iswet.

The scratch resistant particles may be or comprise nano-sized silicaparticles, preferably fused silica particles. The scratch resistantparticles may be disc shaped particles, preferably having awidth/thickness ratio being equal or exceeding 3:1, more preferablybeing equal or exceeding 5:1. Such disc-shaped particles orientate alongthe surface of the foil, thereby improving the scratch resistance of thefoil. The scratch resistant particles may have an average particle sizeof 1-100 μm, preferably 10-50 μm, more preferably 20-30 μm. The scratchresistant particles may have an average particle size of less than 50μm, preferably less than 45 μm. The scratch resistant particles may beapplied in an amount of 0.5-20 g/m2, preferably in an amount of 0.5-10g/m2, more preferably in an amount of 0.5-5 g/m2.

The coating composition may comprise conventional additives. The coatingcomposition may further comprise functional additives, such as anti-statadditives and/or anti-bacterial additives.

The coating composition may be transparent. However, the coatingcomposition may also be pigmented.

The coating composition may be applied as one or several layers on thesecond foil 9.

After the coating composition has been applied on the carrier 1′, thecoating composition is cured such that a coating layer 2 is formed. Ifthe coating composition is UV curable, UV radiation is applied to curethe coating composition. If the coating composition is water-based UVcurable coating composition, the coating composition is first dried in adrying device 21 by IR or in an oven and thereafter is cured by applyingUV radiation 22 to the coating composition in a UV radiation device 22.If the coating composition is a two-component system, the coatingcomposition is dried, for example, in an oven or in room temperature.

After curing, a coated foil 10′ is formed.

Preferably, some crosslinking capacity of the coating compositionremains after curing. The coating composition may have a residualoligomer content of less than 10% after curing. Thereby, during pressingin a subsequent step, the coating composition may be furthercrosslinked.

In one embodiment, the second foil 9 is coated in the above describedway before the first and second foil 8, 9 are adhered to each other,preferably by pressing.

The coated foil 10′ formed by the method described with reference toFIG. 3 may be stored after the coating composition has been cured. Thecoated foil 10′ may be applied to a substrate 3, with an optionaldecorative layer 4, as previously described with reference to FIG. 1B.The coated foil 10′ may be intended to be used as coated wear resistantfoil. In one embodiment, wherein the carrier is decorative thermoplasticfoil, the coated carrier may be a coated decorative foil.

It is contemplated that there are numerous modifications of theembodiments described herein, which are still within the scope of theinvention as defined by the appended claims. For example, it iscontemplated that more than one wear resistant foil may be arranged on acore for forming a building panel. It is also contemplated that anadditional coating layer or layers may be applied after pressing to thepressed coating layer.

It is also contemplated that a building panel being already formed maybe coated by the above described method. In this embodiment, the carrierforms part of a building panel when the coating composition is appliedon the carrier. After the coating composition is applied, the coatingcomposition is cured to a coating layer and thereafter pressed asdescribed above.

An exemplary UV curable water-based composition may include:

-   -   UV curable composition may be 60 to 90 wt % of the composition,        for example, 70 to 85 wt %;    -   Photoinitiator may be 0.1 to 5 wt % of the composition, for        example, 0.5 to 2.5 wt %;    -   Water may be 1 to 25 wt % of the composition, for example, 5 to        15 wt %;    -   Solvent may be 0.1 to 10 wt % of the composition, for example,        0.5 to 10 wt %;    -   Thickener may optionally be used, and may be 0.0 to 15 wt % of        the composition, for example, 0.1 to 10 wt %;    -   Wear resistant particles may optionally be used, and may be 0.0        to 15 wt % of the composition, for example, 0.1 to 10 wt;    -   Matting agent may optionally be used, and may be 0.0 to 15 wt %        of the composition, for example, 0.1 to 10 wt %;    -   Additive (e.g., defoamer/wetting agent) may optionally be used,        and may be 0.0 to 15 wt % of the composition, for example, 0.1        to 10 wt %.

An exemplary solvent may be dipropylene glycol methyl ether.

EXAMPLES Example 1: Lacquered PVC Foil on PVC Foil with Wear ResistantParticles

A first PVC wear layer foil with a thickness of 0.1 mm, was positionedon a decorative PVC foil with a thickness of 0.03 mm. On the first wearlayer foil 25 g/m2 Al₂O₃ particles were applied using a scatteringdevice. A second PVC wear layer foil with a thickness of 0.1 mm, waslacquered with 60 g/m2 UV curable water-based coating compositionaccording to Table 1, dried in 50° C. oven for 10 minutes and then UVcured. The second PVC wear layer foil was positioned on the first wearlayer foil with the Al₂O₃ particles. The decorative foil, the first wearlayer foil and the second wear layer foils were laminated on to a PVCcore material using a temperature of 140° C., a pressure of 10 bars anda pressing time of 60 seconds. The resulting product was found to haveimproved scratch resistance and chemical resistance. The resultingproduct was found to have a wear resistance higher than 5000 revolutionsas tested in a Taber abrader in accordance with the test method inEN13329.

TABLE 1 UV curable water-based composition UV-curablePolyester/Polyurethane Dispersion 56.9 wt % UV-curablePolyurethane/Acrylic Copolymer Dispersion 22.8 wt % Photoinitiator  1.1wt % Water  8.7 wt % Solvent (Dipropylene Glycol Methyl Ether)  2.9 wt %Thickener (PU)  3.3 wt % Al₂O₃  1.1 wt % Matting agent (Silica)  2.2 wt% Additive (defoamer/wetting agent) silicon   1 wt %

Example 2: Lacquered PVC Foil on PVC Foil with Wear Resistant Particlesbeing Pre-Pressed

On a first PVC wear layer foil with a thickness of 0.1 mm, 25 g/m2 Al₂O₃particles were applied using a scattering device. A second PVC wearlayer foil with a thickness of 0.1 mm, was lacquered with 60 g/m2 UVcurable water-based coating composition according to Table 1, dried in50° C. oven for 10 minutes and then UV cured. The second PVC wear layerfoil was positioned on the first wear layer foil with the Al₂O₃particles. The first and the second wear layer foil were laminated usinga temperature of 120° C., a pressure of 10 bars and a pressing time of60 seconds in a first pressing step. The laminated wear layer waslaminated on to a decorative PVC foil with a thickness of 0.03 mm and toa PVC core material using a temperature of 140° C., a pressure of 10bars and a pressing time of 60 seconds in a second pressing step. Theresulting product was found to have improved scratch resistance andchemical resistance. The resulting product was found to have a wearresistance higher than 5000 revolutions as tested in a Taber abrader inaccordance with the test method in EN13329.

Example 3: Lacquered PVC Foil on PVC Foil being Pre-Pressed

A first PVC wear layer foil with a thickness of 0.1 mm. A second PVCwear layer foil with a thickness of 0.1 mm, was lacquered with 60 g/m2UV curable water-based coating composition according to Table 1, driedin 50° C. oven for 10 minutes and then UV cured. The second PVC wearlayer foil was positioned on top of the first PVC wear layer foil. Thefirst and the second wear layer foils were laminated using a temperatureof 120° C., a pressure of 10 bars and a pressing time of 60 seconds in afirst pressing step. The laminated wear layer was laminated on to a PVCdecorative foil with a thickness of 0.03 mm and a PVC core materialusing a temperature of 140° C., a pressure of 10 bars and a pressingtime of 60 seconds in a second pressing step. The resulting product wasfound to have improved scratch resistance and chemical resistance. Theresulting product was found to have a wear resistance higher than 1900revolutions as tested in a Taber abrader in accordance with the testmethod in EN13329.

Example 4: Lacquered PVC Foil on PVC Foil

A first PVC wear layer foil with a thickness of 0.1 mm was positioned ona decorative PVC foil with a thickness of 0.03 mm. A second PVC wearlayer foil with a thickness of 0.1 mm, was lacquered with 60 g/m2 UVcurable water-based coating composition according to Table 1, dried in50° C. oven for 10 minutes and then UV cured. The second PVC wear layerfoil was positioned on top of the first PVC wear layer foil. The firstand the second wear layer foils were laminated on to a PVC core materialusing a temperature of 140° C., a pressure of 10 bars and a pressingtime of 60 seconds. The resulting product was found to have improvedscratch resistance and chemical resistance. The resulting product wasfound to have a wear resistance higher than 1900 revolutions as testedin a Taber abrader in accordance with the test method in EN13329.

Example 5: Lacquered PU Foil on PVC Foil with Wear Resistant Particles

A PVC wear layer foil with a thickness of 0.1 mm was positioned on adecorative foil with a thickness of 0.03 mm. On the PVC wear layer foil25 g/m2 Al₂O₃ particles were applied using a scattering device. A PUwear layer foil with a thickness of 0.05 mm, was lacquered with 60 g/m2UV curable water-based coating composition according to Table 1, driedin 50° C. oven for 10 minutes and then UV cured. This PU wear layer foilwas positioned on the PVC wear layer foil with the Al₂O₃ particles. ThePU wear layer foil and the PVC wear layer foil were laminated on to aPVC core material using a temperature of 140° C., a pressure of 10 barsand a pressing time of 60 seconds. The resulting product was found tohave improved scratch resistance and chemical resistance. The resultingproduct was found to have a wear resistance higher than 5000 revolutionsas tested in a Taber abrader in accordance with the test method inEN13329.

Example 6: Lacquered PU Foil on PVC Foil with Abrasive Particles beingPre-Pressed

On a PVC wear layer foil with a thickness of 0.1 mm 25 g/m2 Al₂O₃particles was applied using a scattering device. A PU wear layer foilwith a thickness of 0.05 mm, was lacquered with 60 g/m2 UV curablewater-based coating composition according to Table 1, dried in 50° C.oven for 10 minutes and then UV cured. This PU wear layer foil waspositioned on the PVC wear layer foil with the Al₂O₃ particles. The twofoils were laminated using a temperature of 120° C., a pressure of 10bars and a pressing time of 60 seconds in a first pressing step. Thelaminated wear layer was laminated on to a decorative PVC foil with athickness of 0.03 mm and a PVC core material using a temperature of 140°C., a pressure of 10 bars and a pressing time of 60 seconds in a secondpressing step. The resulting product was found to have improved scratchresistance and chemical resistance. The resulting product was found tohave a wear resistance higher than 5000 revolutions as tested in a Taberabrader in accordance with the test method in EN13329.

Example 7: Lacquered PU Foil on PVC Foil being Pre-Pressed

A PVC wear layer foil with a thickness of 0.1 mm. A PU wear layer foilwith a thickness of 0.05 mm, was lacquered with 60 g/m2 UV curablewater-based coating composition according to Table 1, dried in 50° C.oven for 10 minutes and then UV cured. This PU wear layer foil waspositioned on top of the PVC wear layer foil. The two foils werelaminated using a temperature of 120° C., a pressure of 10 bars and apressing time of 60 seconds in a first pressing step. The laminated wearlayer was laminated on to a decorative PVC foil with a thickness of 0.03mm and a PVC core material using a temperature of 140° C., a pressure of10 bars and a pressing time of 60 seconds in a second pressing step. Theresulting product was found to have improved scratch resistance andchemical resistance. The resulting product was found to have a wearresistance higher than 2100 revolutions as tested in a Taber abrader inaccordance with the test method in EN13329.

Example 8: Lacquered PU Foil on PVC Foil

A PVC wear layer foil with a thickness of 0.1 mm was positioned on adecorative PVC foil with a thickness of 0.03 mm. A PU wear layer foilwith a thickness of 0.05 mm, was lacquered with 60 g/m2 UV curablewater-based coating composition according to Table 1, dried in 50° C.oven for 10 minutes and then UV cured. This PU wear layer foil waspositioned on top of the PVC wear layer foil. The three foils werelaminated on to a PVC core material using a temperature of 140° C., apressure of 10 bars and a pressing time of 60 seconds. The resultingproduct was found to have improved scratch resistance and chemicalresistance. The resulting product was found to have a wear resistancehigher than 2100 revolutions as tested in a Taber abrader in accordancewith the test method in EN13329.

Example 9: Lacquered PVC Wear Layer

A PVC wear layer was lacquered with 60 g/m2 UV curable water-basedcomposition according to Table 1, dried in 50° C. oven for 10 minutesand then UV cured. The lacquered PVC wear layer was pressed using atemperature of 140° C., a pressure of 10 bars and a pressing time of 60seconds. The lacquered wear layer was laminated on to a decorative PVCfoil with a thickness of 0.03 mm and to a PVC core material using atemperature of 140° C., a pressure of 10 bars and a pressing time of 60seconds in a second pressing step. The resulting product was found tohave improved scratch resistance and chemical resistance. The resultingproduct was found to have a wear resistance higher than 5000 revolutionsas tested in a Taber abrader in accordance with the test method inEN13329.

Example 10: Lacquered LVT with PVC Wear Layer

An LVT product comprising a PVC core material and a decorative PVC foilwith a PVC wear layer on top, was lacquered with 60 g/m2 UV curablewater-based composition according to Table 1, dried in 50° C. oven for10 minutes and then UV cured. This lacquered LVT was pressed using atemperature of 140° C., a pressure of 10 bars and a pressing time of 60seconds. The LVT product was found to have improved scratch resistanceand chemical resistance. The LVT product was found to have a wearresistance higher than 5000 revolutions as tested in a Taber abrader inaccordance with the test method in EN13329.

Example 11: Lacquered LVT with PU Wear Layer

An LVT product comprising a PVC core material and a decorative PVC foilproduct with a PU wear layer on top, was lacquered with 60 g/m2 UVcurable water-based composition according to Table 1, dried in 50° C.oven for 10 minutes and then UV cured. This lacquered LVT was pressedusing a temperature of 140° C., a pressure of 10 bars and a pressingtime of 60 seconds. The LVT product was found to have improved scratchresistance and chemical resistance. The LVT product was found to have awear resistance higher than 5000 revolutions as tested in a Taberabrader in accordance with the test method in EN13329.

Example 12: Lacquered PU Wear Layer on Veneer

A wood veneer layer having a thickness of 0.6 mm was adhered to a PVCcore material by a PU powder. A first PU wear layer foil having athickness of 0.05 mm was arranged on the wood veneer layer. On the firstPU wear layer foil 25 g/m2 Al₂O₃ particles were applied using ascattering device. A second PU wear layer having a thickness of 0.05 mmwas applied on the PU wear layer foil with the Al₂O₃ particles. Thesecond PU wear layer foil was lacquered with 60 g/m2 UV curablewater-based coating composition according to Table 1, dried in 50° C.oven for 10 minutes and then UV cured. The wood veneer layer, the firstPU wear layer foil and the second lacquered PU wear layer foil werelaminated to the PVC core material using a temperature of 140° C., apressure of 10 bars and a pressing time of 60 seconds. The resultingproduct was found to have improved scratch resistance and chemicalresistance. The resulting product was found to have a wear resistancehigher than 2400 revolutions as tested in a Taber abrader in accordancewith the test method in EN13329.

Example 13: Lacquered PVC Foil on PVC Foil

A first PVC wear layer foil with a thickness of 0.1 mm was positioned ona decorative PVC foil with a thickness of 0.03 mm. A second PVC wearlayer foil with a 15 thickness of 0.1 mm, was lacquered with 60 g/m22-component (PU-isocyanate) water-based coating composition dried in 50°C. oven for 20 minutes and then in RT for 2 days. The second PVC wearlayer foil was positioned on top of the first PVC wear layer foil. Thefirst and the second wear layer foils were laminated on to a PVC corematerial using a temperature of 140° C., a pressure of 10 bars and apressing time of 60 seconds. The resulting product was found to haveimproved scratch resistance and chemical resistance. The resultingproduct was found to have a wear resistance higher than 1900 revolutionsas tested in a Taber abrader in accordance with the test method inEN13329.

Embodiments

1. A method to produce a coating layer (2), comprising

applying a water-based coating composition on a surface of a carrier (1;1′),

curing the water-based coating composition to a coating layer (2),

subsequently applying pressure to the coating layer (2).

2. The method according to embodiment 1, wherein the carrier (1; 1′)comprises a thermoplastic material.3. The method according to embodiment 1 or 2, wherein applying pressurecomprises pressing the coating composition against a pressing device(23) comprising portions having different gloss levels, such that thecoating layer (2) obtains different gloss levels after pressing.4. The method according to any one of embodiments 1-3, wherein applyingpressure comprises applying heat and pressure simultaneously.5. The method according to any one of embodiments 1-4, wherein thecoating composition comprises a cross-linkable component.6. The method according to any one of embodiments 1-5, wherein thecoating composition is UV-curable.7. The method according to any one of embodiments 1-5, wherein thecoating composition comprises a two-component system.8. The method according to any one of embodiments 1-7, wherein thecarrier is a foil (1), preferably a thermoplastic foil.9. The method according to any one of embodiments 1-8, wherein applyingpressure to the coating composition comprises pressing and attaching thecoating layer (2) on the carrier (1; 1′) to a substrate (3), wherein thecarrier (1; 1′) is intermediate the coating layer (2) and the substrate(3).10. The method according to any one of embodiments 1-8, furthercomprising releasing the coating layer (2) from the carrier (1; 1′)prior to applying pressure, and wherein applying pressure to the coatinglayer (2) comprises pressing and attaching the coating layer (2) to asubstrate (3).11. The method according to any one of embodiments 1-10, wherein thecoating composition comprises wear resistant particles and/or scratchresistant particles.12. The method according to any one of embodiments 1-11, wherein thecarrier (1′) comprises a first thermoplastic foil (8) and a secondthermoplastic foil (9), wherein wear resistant particles, preferablyaluminium oxide particles, are arranged between the first and the secondfoil (8, 9).13. The method according to any one of embodiments 1-12, wherein thecoating layer (2) is substantially transparent.14. A method to produce a coating layer (2), comprising

applying a coating composition on a surface of a carrier (1; 1′),wherein the carrier (1; 1′) is a thermoplastic foil,

curing the coating composition to a coating layer (2),

subsequently applying pressure to the coating layer (2).

15. The method according to embodiment 14, wherein the coatingcomposition is UV-curable, preferably a water-based UV curable coatingcomposition.16. A method to produce a building panel (5), comprising

providing a substrate (3) and at least one surface layer (1; 1′, 4)arranged on the substrate (3),

applying a water-based coating composition on said at least one surfacelayer (1; 1′, 4),

curing the water-based coating composition such that a coating layer (2)is formed on said at least one surface layer (4),

subsequently applying pressure to the coating layer (2) with a pressingdevice (23), and pressing the substrate (3) and the coated surface layer(1; 1′, 4) together to form a building panel (5).

17. The method according to embodiment 16, wherein said at least onesurface layer comprises a thermoplastic material.18. The method according to embodiment 16 or 17, wherein applyingpressure to the coating layer (2) with the pressing device comprisesapplying heat and pressure simultaneously.19. The method according to any one of embodiments 16-18, whereinapplying pressure to the coating layer (2) with the pressing devicecomprises bonding the substrate (3), said at least surface layer (1; 1′;4) and the coating composition together.20. The method according to any one of embodiments 16-19, wherein thepressing device (23) comprises portions having different gloss levels,such that the coated surface layer (1; 1′, 4) obtains different glosslevels after pressing.21. The method according to any one of embodiments 16-20, wherein thecoating layer (2) is substantially transparent.22. The method according to any one of embodiments 16-21, wherein thecoating composition comprises a cross-linkable component.23. The method according to any one of embodiments 16-22, wherein thecoating composition is UV-curable.24. The method according to any one of embodiments 16-22, wherein thecoating composition comprises a two-component system.25. A method to produce a coated foil (10′), comprising

providing a first thermoplastic foil (8) and a second thermoplastic foil(9),

applying wear resistant particles (6) on the first thermoplastic foil(8) or on a second thermoplastic foil (9),

applying the second thermoplastic foil (9) on the first thermoplasticfoil 8( ) such that the wear resistant particles (6) are arrangedbetween the first and second thermoplastic foil (8, 9),

applying a coating composition on the second thermoplastic foil (9),

curing the coating composition such that a coating layer (2) is formed,and

subsequently applying pressure to the coating layer (2).

26. A coated foil (10, 10′), comprising a carrier (1, 1′) and a curedcoating layer (2) arranged on a surface of the carrier (1, 1′), whereinthe carrier (1, 1′) comprises a thermoplastic material, wherein thecured coating layer (2) comprises an embossed structure and/or differentgloss levels obtained by a pressing device (23) after curing the coatinglayer (2).

27. The coated foil according to embodiment 26, wherein the carriercomprises a first thermoplastic foil (8) and a second thermoplastic foil(9) with wear resistant particles (6) arranged therebetween.28. The coated foil according to any one of embodiments 26-27, whereinthe cured coating layer is cross-linked.29. The coated foil according to any one of embodiments 26-28, whereinthe cured coating layer (2) is UV-cured.30. The coated foil according to any one of embodiments 26-28, whereinthe coating layer comprises a two-component system.31. A building panel (5), comprising

a substrate (3),

at least one surface layer (1; 1′, 4) arranged on the substrate (3),wherein at least one surface layer (1; 1′, 4) comprises a thermoplasticmaterial, and

wherein an uppermost surface layer is provided with a cured coatinglayer (2), wherein the cured coating layer (2) comprises an embossedstructure and/or different gloss levels obtained by a pressing device(23) after curing the coating layer (2).

32. The building panel according to embodiment 31, wherein said at leastone surface layer (1; 1′, 4) comprises at least one a thermoplasticfoil.33. The building panel according to embodiment 31 or 32, wherein thecured coating layer (2) is cross-linked.34. The building panel according to any one of embodiments 31-33,wherein the cured coating layer (2) is UV cured.35. The building panel according to any one of embodiments 31-33,wherein the coating layer comprises a two-component system.

1. A method to produce a coating layer, comprising applying awater-based coating composition on a surface of a carrier, curing thewater-based coating composition to a coating layer, subsequentlyapplying pressure to the coating layer.
 2. The method according to claim1, wherein the carrier comprises a thermoplastic material.
 3. The methodaccording to claim 1, wherein applying pressure comprises pressing thecoating composition against a pressing device comprising portions havingdifferent gloss levels, such that the coating layer obtains differentgloss levels after pressing.
 4. The method according to claim 1, whereinapplying pressure comprises applying heat and pressure simultaneously.5. The method according to claim 1, wherein the coating compositioncomprises a cross-linkable component.
 6. The method according to claim1, wherein the coating composition is UV-curable.
 7. The methodaccording to claim 1, wherein the coating composition comprises atwo-component system.
 8. The method according to claim 1, wherein thecarrier is a foil.
 9. The method according to claim 1, wherein applyingpressure to the coating composition comprises pressing and attaching thecoating layer on the carrier to a substrate, wherein the carrier isintermediate the coating layer and the substrate.
 10. The methodaccording to claim 1, further comprising releasing the coating layerfrom the carrier prior to applying pressure, and wherein applyingpressure to the coating layer comprises pressing and attaching thecoating layer to a substrate.
 11. The method according to claim 1,wherein the coating composition comprises wear resistant particlesand/or scratch resistant particles.
 12. The method according to claim 1,wherein the carrier comprises a first thermoplastic foil and a secondthermoplastic foil, wherein wear resistant particles are arrangedbetween the first and the second foil.
 13. The method according to claim1, wherein the coating layer is substantially transparent.
 14. A methodto produce a coating layer, comprising applying a coating composition ona surface of a carrier, wherein the carrier is a thermoplastic foil,curing the coating composition to a coating layer, subsequently applyingpressure to the coating layer.
 15. The method according to claim 14,wherein the coating composition is UV-curable.
 16. A method to produce abuilding panel, comprising providing a substrate and at least onesurface layer arranged on the substrate, applying a water-based coatingcomposition on said at least one surface layer, curing the water-basedcoating composition such that a coating layer is formed on said at leastone surface layer, subsequently applying pressure to the coating layerwith a pressing device, and pressing the substrate and the coatedsurface layer together to form a building panel.
 17. The methodaccording to claim 16, wherein said at least one surface layer comprisesa thermoplastic material.
 18. The method according to claim 16, whereinapplying pressure to the coating layer with the pressing devicecomprises applying heat and pressure simultaneously.
 19. The methodaccording to claim 16, wherein applying pressure to the coating layerwith the pressing device comprises bonding the substrate, said at leastsurface layer and the coating composition together.
 20. The methodaccording to claim 16, wherein the pressing device comprises portionshaving different gloss levels, such that the coated surface layerobtains different gloss levels after pressing.
 21. The method accordingto claim 16, wherein the coating layer is substantially transparent. 22.The method according to claim 16, wherein the coating compositioncomprises a cross-linkable component.
 23. The method according to claim16, wherein the coating composition is UV-curable.
 24. The methodaccording to claim 16, wherein the coating composition comprises atwo-component system.
 25. A method to produce a coated foil, comprisingproviding a first thermoplastic foil and a second thermoplastic foil,applying wear resistant particles on the first thermoplastic foil or ona second thermoplastic foil, applying the second thermoplastic foil onthe first thermoplastic foil 8( ) such that the wear resistant particlesare arranged between the first and second thermoplastic foil, applying acoating composition on the second thermoplastic foil, curing the coatingcomposition such that a coating layer is formed, and subsequentlyapplying pressure to the coating layer.
 26. A coated foil, comprising acarrier and a cured coating layer arranged on a surface of the carrier,wherein the carrier comprises a thermoplastic material, wherein thecured coating layer comprises an embossed structure and/or differentgloss levels obtained by a pressing device after curing the coatinglayer.
 27. The coated foil according to claim 26, wherein the carriercomprises a first thermoplastic foil and a second thermoplastic foilwith wear resistant particles arranged therebetween.
 28. The coated foilaccording to claim 26, wherein the cured coating layer is cross-linked.29. The coated foil according to claim 26, wherein the cured coatinglayer is UV-cured.
 30. The coated foil according to claim 26, whereinthe coating layer comprises a two-component system.
 31. A buildingpanel, comprising a substrate, at least one surface layer arranged onthe substrate, wherein at least one surface layer comprises athermoplastic material, and wherein an uppermost surface layer isprovided with a cured coating layer, wherein the cured coating layercomprises an embossed structure and/or different gloss levels obtainedby a pressing device after curing the coating layer.
 32. The buildingpanel according to claim 31, wherein said at least one surface layercomprises at least one a thermoplastic foil.
 33. The building panelaccording to claim 31, wherein the cured coating layer is cross-linked.34. The building panel according to claim 31, wherein the cured coatinglayer is UV cured.
 35. The building panel according to claim 31, whereinthe coating layer comprises a two-component system.